Gaugster

By 'keying' do you mean indexing? The stock plug has three ground electrodes, 1 main and 2 auxiliary incase the plug becomes fouled. That being the case, I would say that it would not be of any benefit.

If you index the plugs using shims it will changed the plugs depth in the chamber slightly. This may lead to poor performance. The combustion chamber is designed for direct injection so during normal driving (low-medium RPM, less then WOT) the A/F mixture is a ‘stratified’ type meaning that there is a rich mixture right around the spark plug but the rest of the combustion chamber is lean. This is opposed to the homogenous mixture for regular fuel injection where the A/F ratio is basically the same throughout the whole chamber.

Indexing plugs seems to be more valuable on smaller engines from motorcycles, snowmobiles etc… at least that has been my experience.

Regards,

Gernby

iTrader: (1)

I would expect modern engines and plugs of good quality and design would be manufactured in such a way that the plugs would automatically be properly indexed when installed with the correct torque specs.

lobuxracer

iTrader: (2)

If you're running 20F hotter, there's something wrong with your cooling system. Standard temperature is expected to be maintained under nearly all conditions until you exceed the heat rejection capacity of your radiator. While it's true the radiator isn't anywhere near large enough to shed a continuous 306 hp all day long, it is big enough to handle the load even under track conditions, so I go back to my original statement - if you're running 20 degrees hot, you have another problem to solve before changing your plugs.

Gernby

iTrader: (1)

When I monitored my S2000's coolant temps via OBDII, I saw 20 degree spikes pretty regularly. When I autocrossed with the BMW club in Mineral Wells, TX, they always had really long, fast courses. After pulling into the paddock at idle, coolant temp would jump more than 20 degrees, and took quite a while for it to drop. However, I'm sure part of the issue with that was my 10 degree colder Mugen thermostat. All the S2000 owners in Florida and Arizona complained about high coolant temps too.

nabbun

how about the coolant temps during normal driving?

I guess it'd be a good idea to try using colder plugs during auto crossing but using regular plugs for normal driving?

Gernby

iTrader: (1)

My S2000's coolant temps did the same thing on the street when driven agressively. People in Arizona would report coolant temps over 210 F as normal in the summer.

Gaugster

This is the coolant temp of the IS250AWD read from a Innova OBDII scanner. Conditions were 60mph, 2k RPM. The data resolution is very low @ 0.5 seconds. Even when my car was on the dyno the temp was stable from what I remember. Only a few degrees up but this is only the IS250. This data was logged over a one week period where the outside temperature varied from 45°F - 55°F

Engine Coolant Temp °F
Intake+1wk, Intake, Stock
188.6 186.8 186.8
188.6 186.8 186.8
188.6 186.8 186.8
186.8 186.8 186.8
186.8 186.8 186.8
186.8 186.8 186.8
186.8 186.8 186.8
186.8 186.8 186.8
186.8 186.8 186.8
186.8 186.8 186.8
186.8 186.8 186.8

AFAIK - There is no relationship between the engines coolant temperature and the spark plugs heat rating for a engine that is working correctly. The combustion temperture is around 2000°F whereas the coolant temps are around 200°F. It is two different subjects.

CrazyIS

The pulsestar plugs cost me $130.00 It took me a hour to install. You have to take off your intake manifold to get down to the driver side plugs on the 250.
I had a problem though. I installed the plugs saturday morning. everything was fine until sunday night until the VSC Check engine light came on. It seems one of the plugs failed on sunday night. Monday morning I took them all out again and it is obvious one of the plugs was not working right. It didn't have the right golden coloration that the other plugs had after being used. I put my Denzos back in. Pulsestar is sending me a new set.
Though now that my old plugs are back in I miss my pulsestar. There is a defenite difference in power.
You don't have to beleive me. I don't work or sell pulsestar plugs I am just an idiot that will have more power in his 250 once I get my new set in.
I spent some time reading some reviews on these plugs. All I have read is good reports. The only bad things I have read are comments from people who have not tried them, but know alot about cars. SuperStreet Mag tested them out last issue with good reveiws.

Gaugster

It's a bummer that you had a problem. Sorry to hear about that. It would be intesting to know what the root cause of the failure was if you get that information.

I have seen some evaluations of these plugs as well, with a slight gain shown on a dyno. I would only suggest that these cars need some time to make adjustments to any new components. So even before and after dyno's are suspect IMO.

Good luck

Gernby

iTrader: (1)

The only thing left I can say about it is that the sum total of all my "cooling mods" (colder thermostat and fan switch, high pressure radiator cap, 80% water / 20% antifreeze coolant mix, Redline Water Wetter, Hondata Intake Manifold insulating gasket, and one step colder spark plugs) resulted in a car that didn't suffer much at all from summer climate. Before those changes, my car was just as much of a turd as every other S2000 in the summer.

It seems to me that it would be best to run the coldest plug you can that doesn't foul out just to reduce risk of detonation.

Gernby

iTrader: (1)

I just realized that I've left out another important detail about why I would like colder plugs. I'm not wanting to run the stock ~11:1 AFR at WOT, and I believe a step colder plugs would help prevent detonation when I'm tuned more agressively to 12.5 - 13.

lobuxracer

iTrader: (2)

Yep. That's how I've always done it. If the heat range is too hot, it will cause preignition and may even cause detonation. Worst case too cold is the plug fouls and the engine runs like crap.

lobuxracer

iTrader: (2)

This review wouldn't happen to be opposite a full page ad for the product now would it? I'm sure it was an impartial review, magazines have been long known for being very impartial.

CrazyIS

Super Street is the most recent test I have seen, but Modified Mag did a write up and they claim they were in Popular Science.
Modified Mag is similar to Super Street but Popular Science is pretty reputable magazine though I never seen them in Popular Science.
Either way I feel more power and thats all that matters. I payed the money tried them out told you guys my feelings about them. Now you can try them for yourself.

ba-b4

I've read on other forums that others have gotten gains with these plugs but even if they worked I wouldn't install them now that you said one of yours was defective.